(() => {
    interface MyPerson {
        firstName: string,
        lastName: string,
        fullName: string
    }
    let person = {
        firstName: '张',
        lastName: '三',
        fullName: '张三'
    }
    //类型注解
    function showPerson(person: MyPerson) {
        console.log(person.firstName);
        console.log(person.lastName);
        console.log(person.fullName);
    }
    showPerson(person)
})()